Moving extremely heavy loads (at least 100,000 pounds or more per foot) has generally been a complicated task because of the large forces involved in lifting and transporting such heavy loads. When possible, large loads are often transported by disassembling or breaking up the load into multiple smaller loads. However, this break-down and subsequent reassembly process can be very time consuming, especially when a heavy load is only to be moved a small distance, or simply needs to be repositioned.
For heavy loads that need periodic movement or adjustment, devices commonly referred to as “walking machines” or “walkers” were developed. These machines typically move the heavy loads in incremental stages. Walking machines are particularly useful for moving large structures, such as oil rigs, silos, and the like. The oil rigs may need to be moved in order to properly position them over spud holes and well sites in oil fields, or moved to a new location that is undergoing oil exploration.
Walking machines typically use hydraulic lift cylinders to lift the load above a supporting surface, and then move or rotate the load relative to the supporting surface by transporting the load via rollers or tracks in the walking machines. A non-limiting method of using a walking machine to move a heavy load is described and illustrated in U.S. Pat. No. 5,921,336, which is herein incorporated by reference. The '525 patent shows elongated beams under several rollers and lift cylinders, which allows the load from the lift cylinders and rollers to be spread over a large area.
However, it would be desirable for walking machines to be able to move a heavy load in any direction of the support beams and/or fine tune the position of the walking machine in a controlled manner. In addition, it would also be desirable for the load transporting apparatus to rotate in the absence of manual labor.